class Solution:
    def translateNum(self, num: int) -> int:
        if num < 10:
            return 1
        else:
            r = num//100
            if r < 10 or r > 26:
                return self.translateNum(num//10)
            else:
                # 既可以当一个，也可以当两个
                return self.translateNum(num//100) + self.translateNum(num//10)